That's assuming no price cut for PS4 though, right? Promotions seem to show it jumps up quite a bit when the price is lowered.
The price cut scenario is what can get the PS4 barely above 10m.
Promotions show big jumps because they create a sense of urgency, unlike a permanent price cut. What you get with a promotion is a high concentration of sales within a couple of weeks whereas a price cut would have an initial boost that levels off continuously and bottoms out at a baseline that is only slightly higher than before the price cut. That's why promotions don't paint an accurate picture of the effect a price cut would have. A two week long promotion leads to at least twice as many sales as a permanent price cut would see during its first two weeks and said multiplier grows bigger the more promotions there have been between the timing of two permanent price cuts.
Considering how many promotions the PS4 has had already, the effect of a permanent price cut is going to be limited because a lot of the people who were waiting for a cheaper PS4 have had multiple chances to get one already and the absence of a price cut for 3+ years led more and more people to take advantage of promotions.
On top of that we are seeing diminishing returns from these temporary promotions.
In the US, PS4 has been $199 on black Friday week for 3 years in a row and despite adding more value to the bundle each year (2017-no game, 2018-1 game, 2019-3 games) sales have also declined each year.
Then there is December where PS4 was $249 w/3 games for 2 full weeks yet sales were down YoY despite having no discount last year.
The idea that a price cut will stop the declines or cause prolonged legs isnt rational.